Compositions and methods of using a dihydroisoxazole compound that reduces ectoparasite infestations on fish

Abstract

Ectoparasite infestations in fish farming can pose significant challenges and issues for aquaculture operations. This disclosure generally relates to treatment or control of ectoparasite infestations (such as sea lice infestations) on fish (such as salmonids) using a particular dosing regimen of an isoxazoline. In particular, the dosing regimen includes oral administration of the active ingredient: (S)-3-methyl-N-(2-oxo-2-(prop-2-yn-1-ylamino)ethyl)-5-(5-(3,4,5-trichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)thiophene-2-carboxamide, including salts, or N-oxide, or solvates thereof, of structural formula The active ingredient may be administered at a dosage (i.e., in a dose) of from about 0.025 mg/kg/d to about 0.250 mg/kg/d. The dosing regimen may include oral administration from about 3 to about 10 consecutive days.

38 . A composition for the treatment or control of ectoparasite infestation on fish, the composition comprising active ingredient (S)-3-methyl-N-(2-oxo-2-(prop-2-yn-1-ylamino)ethyl)-5-(5-(3,4,5-trichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)thiophene-2-carboxamide, or salts, N-oxide, or solvates thereof, of structural formula 
       
         
           
           
               
               
           
         
         wherein the composition is formulated as a medicated fish feed for oral administration at a dosage of about 0.025 mg/kg/day to about 0.250 mg/kg/day based on average fish body weight. 
       
     
     
         39 . The composition of  claim 38 , wherein the fish is a salmonid. 
     
     
         40 . The composition of  claim 38 , wherein the ectoparasite infestation is a sea lice infestation. 
     
     
         41 . The composition of  claim 40 , wherein the sea lice infestation includes one or more life stages selected from copepodids, chalimi, pre-adults, and adults. 
     
     
         42 . The composition of  claim 38 , wherein the dosage is of about 0.025 mg/kg/day, about 0.050 mg/kg/day, or about 0.125 mg/kg/day. 
     
     
         43 . The composition of  claim 38 , wherein the medicated fish feed is administered at a feed rate ranging from 0.4%-2.6% of the fish body weight per day. 
     
     
         44 . The composition of  claim 38 , wherein the dosage is of about 0.025 mg/kg/day to about 0.125 mg/kg/day. 
     
     
         45 . The composition of  claim 38 , wherein the medicated fish feed is in the form of pellets or granules. 
     
     
         46 . A composition for the treatment or control of ectoparasite infestation on fish, the composition comprising active ingredient (S)-3-methyl-N-(2-oxo-2-(prop-2-yn-1-ylamino)ethyl)-5-(5-(3,4,5-trichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)thiophene-2-carboxamide of structural formula 
       
         
           
           
               
               
           
         
         wherein the composition is formulated as a medicated fish feed for oral administration at a dosage of about 0.025 mg/kg/day to about 0.250 mg/kg/day based on average fish body weight. 
       
     
     
         47 . The composition of  claim 46 , wherein the fish is a salmonid. 
     
     
         48 . The composition of  claim 46 , wherein the ectoparasite infestation is a sea lice infestation. 
     
     
         49 . The composition of  claim 48 , wherein the sea lice infestation includes one or more life stages selected from copepodids, chalimi, pre-adults, and adults. 
     
     
         50 . The composition of  claim 46 , wherein the dosage is of about 0.025 mg/kg/day, about 0.050 mg/kg/day, or about 0.125 mg/kg/day. 
     
     
         51 . The composition of  claim 46 , wherein the medicated fish feed is administered at a feed rate ranging from 0.4%-2.6% of the fish body weight per day. 
     
     
         52 . The composition of  claim 46 , wherein the dosage is of about 0.025 mg/kg/day to about 0.125 mg/kg/day. 
     
     
         53 . The composition of  claim 46 , wherein the medicated fish feed is in the form of pellets or granules. 
     
     
         54 . A composition for the treatment or control of sea lice infestation on salmonids, the composition comprising active ingredient (S)-3-methyl-N-(2-oxo-2-(prop-2-yn-1-ylamino)ethyl)-5-(5-(3,4,5-trichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)thiophene-2-carboxamide of structural formula 
       
         
           
           
               
               
           
         
         wherein the composition is formulated as a medicated fish feed for oral administration at a dosage of about 0.025 mg/kg/day to about 0.250 mg/kg/day based on average fish body weight. 
       
     
     
         55 . The composition of  claim 54 , wherein the sea lice infestation includes one or more life stages selected from copepodids, chalimi, pre-adults, and adults. 
     
     
         56 . The composition of  claim 54 , wherein the dosage is of about 0.025 mg/kg/day to about 0.125 mg/kg/day. 
     
     
         57 . The composition of  claim 54 , wherein the medicated fish feed is in the form of pellets or granules.